Antisocial behavior, aggression and violence are major social and mental health problems with origins in early social development. The development of increasingly effective and efficient preventive and clinical interventions to address these problems has as a prerequisite a clear, detailed understanding of the conditions and processes by which multiple social agents contribute to early development. The goal of the proposed research is to identify and detail the multiple social processes occurring in family and peer interaction that contribute to the development of conduct problems and social competence of children from ages 5 to 7 years. Social processes postulated by three rival theories of social development, coercion-reinforcement, social information processing, and affect regulation, will be intensively assessed as they naturally occur in both the family and peer environments of 5 year old boys and girls. Using a correlational-longitudinal design, the independent, competing and interactive contribution of each of these processes to the development of conduct problems and social competence over the subsequent 2 year period of development will be assessed using structural equation modeling. Child conduct problems and social competence will be defined by indicator derived from multiple agents and methods, all of which share minimal method variance with the measures of the socialization mechanisms.